//
//  WelcomeViewController.swift
//  Zayl--weibo
//
//  Created by 张玉 on 15/9/9.
//  Copyright © 2015年 ZY. All rights reserved.
//

import UIKit
import SDWebImage
class WelcomeViewController: UIViewController {
    /// 图像底部约束
    private var iconBottomCons:NSLayoutConstraint?
    override func viewDidLoad() {
        super.viewDidLoad()

        prepareUI()
          // 加载用户头像
        if let urlString = UserAccount.loadAccount()?.avatar_large {
            // 更新图像，会自动更新imageView的大小
            iconView.sd_setImageWithURL(NSURL(string: urlString))
        }
        
    }
    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
         // 提示：修改约束不会立即生效，添加了一个标记，统一由自动布局系统更新约束
        iconBottomCons?.constant = UIScreen.mainScreen().bounds.height - iconBottomCons!.constant
        // 动画
        UIView.animateWithDuration(1.2, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 5, options: UIViewAnimationOptions(rawValue: 0), animations: { () -> Void in
            // 强制更新约束
            self.view.layoutIfNeeded()
            }){ (_) -> Void in
                
        }
    
    }
    //准备界面
    private func prepareUI() {
        view.addSubview(backImageView)
        view.addSubview(iconView)
        view.addSubview(label)
        
        //自动布局
        //1:背景图片 如果换到5S 上 会出现 图片大小问题 所有要设置
        backImageView.translatesAutoresizingMaskIntoConstraints = false
        view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|-0-[subview]-0-|", options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: ["subview":backImageView]))
        view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|-0-[subview]-0-|", options: NSLayoutFormatOptions(rawValue: 0), metrics:nil, views: ["subview":backImageView]))
        
        
        //2:头像
        iconView.translatesAutoresizingMaskIntoConstraints = false
        view.addConstraint(NSLayoutConstraint(item: iconView, attribute: NSLayoutAttribute.CenterX, relatedBy: NSLayoutRelation.Equal, toItem: view, attribute: NSLayoutAttribute.CenterX, multiplier: 1.0, constant: 0))
        view.addConstraint(NSLayoutConstraint(item: iconView, attribute: NSLayoutAttribute.Width, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 1.0, constant: 90))
        view.addConstraint(NSLayoutConstraint(item: iconView, attribute: NSLayoutAttribute.Height, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 1.0, constant: 90))
        view.addConstraint(NSLayoutConstraint(item: view, attribute: NSLayoutAttribute.Bottom, relatedBy: NSLayoutRelation.Equal, toItem: iconView, attribute: NSLayoutAttribute.Bottom, multiplier: 1.0, constant: 160))
        // 记录底边约束
        iconBottomCons = view.constraints.last

        
        
        //3:标签
        label.translatesAutoresizingMaskIntoConstraints = false
        view.addConstraint(NSLayoutConstraint(item: label, attribute: NSLayoutAttribute.CenterX, relatedBy: NSLayoutRelation.Equal, toItem: iconView, attribute: NSLayoutAttribute.CenterX, multiplier: 1.0, constant: 0))
        view.addConstraint(NSLayoutConstraint(item: label, attribute: NSLayoutAttribute.Top, relatedBy: NSLayoutRelation.Equal, toItem: iconView, attribute: NSLayoutAttribute.Bottom, multiplier: 1.0, constant: 16))
        
    }
    

    
    // MARK: 懒加载控件
    //背景图片
    private lazy var backImageView:UIImageView = UIImageView(image: UIImage(named: "ad_background"))
    
    //用户头像
    private lazy var iconView:UIImageView = {
        let iv = UIImageView(image: UIImage(named: "avatar_default_big"))
        //设置圆角 超出主Layout 剪裁掉
        iv.layer.masksToBounds = true
        iv.layer.cornerRadius = 45
        return iv
    }()
    /// 消息文字
    private lazy var label:UILabel = {
        let label = UILabel()
        label.text = "欢迎回来"
        label.sizeToFit()
        return label
    }()

    
}
